Such a receiver and filter arrangement are known from U.S. Pat. No. 4,723,318. In receivers an RF signal is down converted to an IF frequency substantially lower than said RF frequency in order to make it possible to obtain a good adjacent channel selectivity with easy realizable filters. A problem associated with this down conversion is the sensitivity of the receiver for so-called image signals. If the signal to be received has a frequency of f.sub.RF, the local oscillator to be used in the frequency conversion means has a frequency f.sub.LO and the IF frequency is equal to f.sub.LO -f.sub.RF, the receiver receives also RF signals with a frequency of f.sub.LO +f.sub.IF, causing interference to the reception of the desired RF signal with frequency f.sub.RF.
In order to suppress this undesired effect, often an RF filter is used in front of the frequency conversion means to suppress RF signals with a frequency of f.sub.LO +f.sub.IF. This RF filter can be quite expensive.
In the receiver according to the above mentioned US patent, a so called polyphase filter is used for filtering the output signal of the frequency conversion means. Polyphase filters can make use of multiple phase shifted input signals (to be provided by the frequency conversion means) to produce asymmetric transfer functions enabling suppression of signals at the image frequency without requiring an RF filter. The polyphase filter according to the above mentioned US patent is designed for suppressing a signal at an image frequency.